Catheters, and in particular catheters for locoregional anaesthesia, are small in diameter, most often of the order of 0.43*0.80 mm, 0.50*0.90 mm or even 0.50*1.00 mm, and made of relatively elastic material especially to avoid the plication problems. Given the small dimension of these catheters, they are therefore difficult to block ergonomically in a base. But this is necessary if the aim is to connect the catheter to a medical device, such as a filter within the scope of locoregional anaesthesia.
It has therefore been proposed to use a base, comprising a body adapted for housing a sleeve made of elastomer material, having an internal aperture designed to receive the catheter, and able to be compressed by means of a nut by screwing. The radial compression of the sleeve by the nut in fact holds the catheter in position in the base. This type of base is for example illustrated in patent application FR 2 896 698 in the name of the applicant.
In use, the applicant noted that the nut compressing the sleeve risked being lost, especially when the latter is unscrewed to enable introduction of the catheter in the compressible sleeve. It is no longer possible to use the base, or at least the lost piece should be replaced. Also, during screwing, the nut risks pulling along the compressible sleeve in rotation by twisting it on itself, such that once the catheter is blocked, the sleeve risks resuming its initial form by pulling along the nut in turn, releasing the stress applied to the catheter, which can be harmful to proper mechanical behaviour of the catheter in the base.
Also, when the base is fixed to a medical device such as a filter and the latter must be changed or simply pulled out, unscrewing the medical device from the nozzle (generally of standard Luer or Luer Lock type) of the base can cause the unscrewing of the nut, to the extent where it is necessary to hold the base by the nozzle during unscrewing of the medical device.
The applicant has also noted that it was difficult to determine if the catheter were correctly held in the base, to the extent where nothing confirms that the nut is sufficiently screwed on the compressible sleeve or the catheter is correctly inserted in the base. Also, such screwing today is not considered ergonomic.
It has also been proposed to utilise a base comprising a relatively thin tubular sleeve, having a central aperture whereof the diameter is substantially equal to that of the catheter to be blocked, and designed to be compressed radially.
For example, document WO 2011/106077 proposes a system comprising a base, comprising a deformable thin sleeve adapted to receive a catheter and a shell fitted with internal grooves. The shell is mounted in rotation on the base and adapted to radially deform the sleeve by means of the internal grooves when it is closed on the base so as to locally reduce the internal diameter of the sleeve and block the catheter in position.
Document US 2003/0225379 describes a valve adapted to detachably receive a catheter and, when necessary, prevent the passage of fluids in this catheter. For this purpose, the valve comprises a base adapted to receive the catheter, and a shell, mounted in translation on the base between an open position, in which the shell is away from the base, and a closed position, in which the shell is hooked on the base and blocks the catheter in position. The base defines a housing enclosing a sleeve provided with a blocking aperture adapted to receive the catheter. The system also comprises an actuator mobile in translation in the housing between a rest position and a blocking position in which the actuator applies a transversal force to the sleeve to deform it locally. In this accurate blocking position, the actuator also deforms the catheter to prevent the passage of fluids.